VOL.
No.
ii,
2
COMPUTERIZED VASCULAR
TRANSVERSE LESIONS PART
By BARRY
D.
PRESSMAN,
M.D.,
II:
OF
OF
ANEURYSMS
GEORGE
E.
GILBERT,
WASHINGTON,
C
American Journal of Roentgenology 1975.124:215-219.
TOMOGRAPHY THE BRAIN*
D.
and
M.D.,
DAV!D
0.
DAVIS,
M.D.
C.
OMPUTERIZED transverse tomography (CTT) of the brain has been described fully elsewhere in the literature.’4 A discussion of the absorption coefficient convention utilized is to be found in Part i of this report. Herein are presented 4 cases of intracranial aneurysms studied by CTT. These indicate that there is a role for CTT in the
ciated
diagnosis
atrophy and a left temporal hemianopsia. There was erosion of the left side of the sella turcica as well as a thin linear calcification immediately posterior to the posterior clinoid. A radionuclide brain scan was positive in the suprasellar region and cerebral arteriography demonstrated a I6X2o mm. aneurysm of the left supraclinoid carotid artery. This lesion was also clearly delineated as a 23 X 27 mm. area of increased density (absorption coefficients: +22 to +28) on CTT.
and
intracranial
evaluation
of
patients
with
aneurysms. REPORT
OF
CASES
CASE I (Fig. I). A 6 year old female underwent CTT for evaluation of right ophthalmoplegia and slight proptosis. CTT demonstrated a round (21 mm. in diameter), dense lesion (absorption coefficients: +20 to +26) just above,
behind
and to the right
of the dorsum
sellae.
On
angiography, this lesion proved to be an aneurysm arising from the junction of the right posterior cerebral and posterior communicating arteries, measuring I2X2o mm. There was mass effect upon the right superior cerebellar artery and upon the thalamoperforate arteries, indicating the presence of mural thrombus or associated
hematoma
aneurysm
appeared
angiogram. Surgery mural thrombus.
and
larger
explaining
why
on CTT
confirmed
hemorrhage.
The
radionuclide
brain
scan
in the region
+31)
of the anterior
lobe. A I2X2o mm. aneurysm the left middle cerebral artery strated by angiography. There *
ton,
From
the
Department
of Radiology,
tion.
CASE
plained
year
film roentgenograms any mural
the aneurysm, between the
(Fig.
III
3).
She was
iv
(Fig. because Dynamic
calcificaplaques
explaining angiogram
the and
A year old female comdecrease in vision over a
of gradual
period.
found
to have
right
optic
4). A 17 year old male was of right upper extremity focal and static technetium brain
scanning suggested a vascular lesion in the distribution of the left middle cerebral artery. Angiography demonstrated a 20X49 mm. fusi-
the
form aneurysm involving the left middle cerebral artery from its origin to the genu. This area was visualized on CTT as a 30X50 mm. oval density (absorption coefficients: +20 to + 104) in the distribution of the left middle cerebral
artery.
was
CASE
temradio+25 to
sented symptoms
cerebral
left temporal
negative.
at the genu of was demonwas no asso-
rounded
Neuroradiology
the plain
were seen within size discrepancy the CTT.
CASE
CASE II (Fig. 2). This 49 year old female was lethargic and had a stiff neck. Lumbar puncture was equivocal for the presence of subarachnoid
positive in the region of the left anterior poral lobe. CTT revealed a X 20 mm. dense lesion (absorption coefficients:
and
area did not demonstrate At surgery, thrombotic
evaluated seizures.
than on the presence of
the
mass
of this
Section,
215
5). This
62 year
multiple suggesting
peduncle. CTT
dense
left
smoothly of the midline
The
George
+24),
D. C.
v (Fig.
with
neurological
preand
a lesion
involving
the
left
Radionuclide
brain
scan
was
demonstrated
(absorption
Washington
old female signs
marginated and in the University
a
mm.
20X24
coefficients:
+20
lesion location
just to the of the left
Medical
Center,
Washing-
to
American Journal of Roentgenology 1975.124:215-219.
p
I
FIG.
2.
Case
(A) An area of density (arrow) is above the base of the skull in the
II.
visualized
just
lateral anterior fossa. (B) Left the genu.
aspect
middle
of the
left
cerebral
middle
artery
crania!
aneurysm
at
0 FIG.
i.
Case
density the right
base
I.
(A)
A rounded
area
of increased
is present on this CT’!’ obtained just of the skull. The density is located
and
immediately
sellae (not seen angiogram. An
on
posterior
this
aneurysm
section).
at
to
the
(B) Left the junction
above to the dorsum
vertebral
cerebral creased
peduncle. markedly
+43)
to
after
administered.
mm. to
The density (absorption
intravenous
contrast
Angiography
aneurysm
the
of
the
of the lesion coefficients: medium
revealed
basilar
a
artery
in+22
was 20X23
extending
left.
of the
right posterior cerebral and posterior communicating arteries with associated surrounding mass effect (arrows indicate stretched superior cerebellar and thalamoperforate vessels).
DISCUSSION
Each CTT
of has
been
the
aneurysms relatively
visualized large
and
each
by had
VOL.
124,
No.
Computerized
2
Transverse
Tomography:
I. .‘.:3
-
American Journal of Roentgenology 1975.124:215-219.
F--.-
T’
-
,.
-.
#{149}.--
Part
‘1
II
217
B. D. Pressman,
American Journal of Roentgenology 1975.124:215-219.
218
&
a
G. E.
Gilbert
and
D. 0.
Davis
JUNE,
5975
VOL.
No.
124,
Computerized
2
Transverse
Tomography:
coefficients greater than +20. be accounted for by the presence thrombus or calcification. Corroboration of this is indicated by : the surgical findings of mural thrombus in Cases i and II; the roentgenologic findings of calcification in the aneurysm in Case III; and the larger appearance of the aneurysm on CT’I’ than on angiography in Cases I-IV. Further, it is well known that mural thrombus or calcification is frequently present in aneurysms, particularly large aneurysms. However, an alternate explanation for the increased density of the aneurysms
American Journal of Roentgenology 1975.124:215-219.
absorption This can of mural
relates
to
blood.
Although
the
absorption this
coefficient
is not
yet
without
presented.
But,
we
have
not
visualized
indicating
the
the
subarachnoid
CTT
more,
tion
of
sellae
may
a
on
give
lesion
CTT
is an excellent intracerebral the detection
tion nately,
for
rysms
by
this
CTT
ministering
contrast
time this is only The diagnosis
for
smaller
by
scanning
cases
since
may
it
agents.
presumption. of aneurysm
At
after the
evaluation
ciated
hematomas,
a lesion the location and shape of the lesion as well as by the clinical history, but the findings are not specific and angiography is necessary to delineate the nature of the lesion. CTT may, however, offer valuable complementary information to the angiogram: (a) a more accurate indication of the size of the aneurysm with mural thrombus is available from CT’!’. since it detects the wall rather seen
on
CTT
can
be
suggested
for
by
angi-
is not
delineated.
Barry
D. Pressman,
need
for
with
asso-
even
or
ifthe
aneurysm
M.D.
of Radiology
The
for
the
patients
Neveraneurysm
encephalomalacia
itself
tion
in
indicate
dilatation,
authors
to Dr.
high.
useful
in
ventricular
wish
Todd on
the
University
to express
Klopper
Case
and
III
appreciation
for providing
angiogram
to
on
Dr.
inform
Thomas
a-
Dma
v.
Case
REFERENCES
J. Computerized
AMBROSE,
ning
ad-
present
the
examinaUnfortusmall aneu-
is not be
may
further
Department
aneurysms
to
screening disease. rate of
procedure
CTT
theless,
i.
of
direction
CONCLUSION
sensitivity
increased
for
Further-
CTT.
The George Washington Medical Center 901 23rd Street, N.W. Washington, D. C. 20037
be
responsible
as in Cases I and v, circulation might not were it not for the detecposterior to the dorsum
small aneurysms at the base of the brain and it appears clear that CTT will not satisfactorily call attention to small aneurysms in any location unless there is an associated hematoma or edema. As is discussed in Part i, and also demonstrated by Case v, the vascular nature of a lesion may be indicated by an increase in its density after intravenous administration of iodinated agents. It is possible then that the would
one
hemorrhage.
ographic procedure where the posterior have been studied
data indicate absorption
ones
219
lumen as in angiography; (b) the of a hematoma may easily be detected. The latter may be very useful when angiography defines multiple aneurysms
recent
that extravascular blood has coefficients ranging up to the mid 2O’S. It is suggested that intravascular blood may also have absorption coefficients in this range, particularly in patients with a normal or high normal hematocrit. In over I ,700 cases, we have not yet been aware of a false negative CTT in patients with aneurysms as large or larger than the
II
than the presence
of
clear,
Part
(tomography):
transverse Part
2:
scan-
axial
Clinical
applica-
Brit. 7. Radiol., 1973, 46, 1023-1047. D. 0., and PRESSMAN, B. D. Computerized tomography of brain. Radiol. C/in. North Amertion.
2.
DAVIS,
ica, 1974, 3. HOUNSFIELD, axial
12,
297-313.
G.
scanning
N.
Computerized
transverse
(tomography):
tion of system.
Brit.
Part
7. Radiol.,
i.
1973,
Descrip46, 1016-
1022.
4.
NEW, DAVIS,
ized .
F. J., Scoi-r, W. R., SCHNUR, J. A., K. R., and ‘IAVERAS, J. M. Computeraxial tomography with EM! scanner.
P.
Radiology, 1974, 110, 109-123. Scorr, W. R., NEW, P. F. and
raphy
SCHNUR,
of
hemorrhage.
J.
A.
J.,
Computerized
intracerebral Radiology,
and 1974,
DAvIS, axial
K. tomog-
intraventricular ff2,
73-80.
R.,
No.
ii,
2
COMPUTERIZED VASCULAR
TRANSVERSE LESIONS PART
By BARRY
D.
PRESSMAN,
M.D.,
II:
OF
OF
ANEURYSMS
GEORGE
E.
GILBERT,
WASHINGTON,
C
American Journal of Roentgenology 1975.124:215-219.
TOMOGRAPHY THE BRAIN*
D.
and
M.D.,
DAV!D
0.
DAVIS,
M.D.
C.
OMPUTERIZED transverse tomography (CTT) of the brain has been described fully elsewhere in the literature.’4 A discussion of the absorption coefficient convention utilized is to be found in Part i of this report. Herein are presented 4 cases of intracranial aneurysms studied by CTT. These indicate that there is a role for CTT in the
ciated
diagnosis
atrophy and a left temporal hemianopsia. There was erosion of the left side of the sella turcica as well as a thin linear calcification immediately posterior to the posterior clinoid. A radionuclide brain scan was positive in the suprasellar region and cerebral arteriography demonstrated a I6X2o mm. aneurysm of the left supraclinoid carotid artery. This lesion was also clearly delineated as a 23 X 27 mm. area of increased density (absorption coefficients: +22 to +28) on CTT.
and
intracranial
evaluation
of
patients
with
aneurysms. REPORT
OF
CASES
CASE I (Fig. I). A 6 year old female underwent CTT for evaluation of right ophthalmoplegia and slight proptosis. CTT demonstrated a round (21 mm. in diameter), dense lesion (absorption coefficients: +20 to +26) just above,
behind
and to the right
of the dorsum
sellae.
On
angiography, this lesion proved to be an aneurysm arising from the junction of the right posterior cerebral and posterior communicating arteries, measuring I2X2o mm. There was mass effect upon the right superior cerebellar artery and upon the thalamoperforate arteries, indicating the presence of mural thrombus or associated
hematoma
aneurysm
appeared
angiogram. Surgery mural thrombus.
and
larger
explaining
why
on CTT
confirmed
hemorrhage.
The
radionuclide
brain
scan
in the region
+31)
of the anterior
lobe. A I2X2o mm. aneurysm the left middle cerebral artery strated by angiography. There *
ton,
From
the
Department
of Radiology,
tion.
CASE
plained
year
film roentgenograms any mural
the aneurysm, between the
(Fig.
III
3).
She was
iv
(Fig. because Dynamic
calcificaplaques
explaining angiogram
the and
A year old female comdecrease in vision over a
of gradual
period.
found
to have
right
optic
4). A 17 year old male was of right upper extremity focal and static technetium brain
scanning suggested a vascular lesion in the distribution of the left middle cerebral artery. Angiography demonstrated a 20X49 mm. fusi-
the
form aneurysm involving the left middle cerebral artery from its origin to the genu. This area was visualized on CTT as a 30X50 mm. oval density (absorption coefficients: +20 to + 104) in the distribution of the left middle cerebral
artery.
was
CASE
temradio+25 to
sented symptoms
cerebral
left temporal
negative.
at the genu of was demonwas no asso-
rounded
Neuroradiology
the plain
were seen within size discrepancy the CTT.
CASE
CASE II (Fig. 2). This 49 year old female was lethargic and had a stiff neck. Lumbar puncture was equivocal for the presence of subarachnoid
positive in the region of the left anterior poral lobe. CTT revealed a X 20 mm. dense lesion (absorption coefficients:
and
area did not demonstrate At surgery, thrombotic
evaluated seizures.
than on the presence of
the
mass
of this
Section,
215
5). This
62 year
multiple suggesting
peduncle. CTT
dense
left
smoothly of the midline
The
George
+24),
D. C.
v (Fig.
with
neurological
preand
a lesion
involving
the
left
Radionuclide
brain
scan
was
demonstrated
(absorption
Washington
old female signs
marginated and in the University
a
mm.
20X24
coefficients:
+20
lesion location
just to the of the left
Medical
Center,
Washing-
to
American Journal of Roentgenology 1975.124:215-219.
p
I
FIG.
2.
Case
(A) An area of density (arrow) is above the base of the skull in the
II.
visualized
just
lateral anterior fossa. (B) Left the genu.
aspect
middle
of the
left
cerebral
middle
artery
crania!
aneurysm
at
0 FIG.
i.
Case
density the right
base
I.
(A)
A rounded
area
of increased
is present on this CT’!’ obtained just of the skull. The density is located
and
immediately
sellae (not seen angiogram. An
on
posterior
this
aneurysm
section).
at
to
the
(B) Left the junction
above to the dorsum
vertebral
cerebral creased
peduncle. markedly
+43)
to
after
administered.
mm. to
The density (absorption
intravenous
contrast
Angiography
aneurysm
the
of
the
of the lesion coefficients: medium
revealed
basilar
a
artery
in+22
was 20X23
extending
left.
of the
right posterior cerebral and posterior communicating arteries with associated surrounding mass effect (arrows indicate stretched superior cerebellar and thalamoperforate vessels).
DISCUSSION
Each CTT
of has
been
the
aneurysms relatively
visualized large
and
each
by had
VOL.
124,
No.
Computerized
2
Transverse
Tomography:
I. .‘.:3
-
American Journal of Roentgenology 1975.124:215-219.
F--.-
T’
-
,.
-.
#{149}.--
Part
‘1
II
217
B. D. Pressman,
American Journal of Roentgenology 1975.124:215-219.
218
&
a
G. E.
Gilbert
and
D. 0.
Davis
JUNE,
5975
VOL.
No.
124,
Computerized
2
Transverse
Tomography:
coefficients greater than +20. be accounted for by the presence thrombus or calcification. Corroboration of this is indicated by : the surgical findings of mural thrombus in Cases i and II; the roentgenologic findings of calcification in the aneurysm in Case III; and the larger appearance of the aneurysm on CT’I’ than on angiography in Cases I-IV. Further, it is well known that mural thrombus or calcification is frequently present in aneurysms, particularly large aneurysms. However, an alternate explanation for the increased density of the aneurysms
American Journal of Roentgenology 1975.124:215-219.
absorption This can of mural
relates
to
blood.
Although
the
absorption this
coefficient
is not
yet
without
presented.
But,
we
have
not
visualized
indicating
the
the
subarachnoid
CTT
more,
tion
of
sellae
may
a
on
give
lesion
CTT
is an excellent intracerebral the detection
tion nately,
for
rysms
by
this
CTT
ministering
contrast
time this is only The diagnosis
for
smaller
by
scanning
cases
since
may
it
agents.
presumption. of aneurysm
At
after the
evaluation
ciated
hematomas,
a lesion the location and shape of the lesion as well as by the clinical history, but the findings are not specific and angiography is necessary to delineate the nature of the lesion. CTT may, however, offer valuable complementary information to the angiogram: (a) a more accurate indication of the size of the aneurysm with mural thrombus is available from CT’!’. since it detects the wall rather seen
on
CTT
can
be
suggested
for
by
angi-
is not
delineated.
Barry
D. Pressman,
need
for
with
asso-
even
or
ifthe
aneurysm
M.D.
of Radiology
The
for
the
patients
Neveraneurysm
encephalomalacia
itself
tion
in
indicate
dilatation,
authors
to Dr.
high.
useful
in
ventricular
wish
Todd on
the
University
to express
Klopper
Case
and
III
appreciation
for providing
angiogram
to
on
Dr.
inform
Thomas
a-
Dma
v.
Case
REFERENCES
J. Computerized
AMBROSE,
ning
ad-
present
the
examinaUnfortusmall aneu-
is not be
may
further
Department
aneurysms
to
screening disease. rate of
procedure
CTT
theless,
i.
of
direction
CONCLUSION
sensitivity
increased
for
Further-
CTT.
The George Washington Medical Center 901 23rd Street, N.W. Washington, D. C. 20037
be
responsible
as in Cases I and v, circulation might not were it not for the detecposterior to the dorsum
small aneurysms at the base of the brain and it appears clear that CTT will not satisfactorily call attention to small aneurysms in any location unless there is an associated hematoma or edema. As is discussed in Part i, and also demonstrated by Case v, the vascular nature of a lesion may be indicated by an increase in its density after intravenous administration of iodinated agents. It is possible then that the would
one
hemorrhage.
ographic procedure where the posterior have been studied
data indicate absorption
ones
219
lumen as in angiography; (b) the of a hematoma may easily be detected. The latter may be very useful when angiography defines multiple aneurysms
recent
that extravascular blood has coefficients ranging up to the mid 2O’S. It is suggested that intravascular blood may also have absorption coefficients in this range, particularly in patients with a normal or high normal hematocrit. In over I ,700 cases, we have not yet been aware of a false negative CTT in patients with aneurysms as large or larger than the
II
than the presence
of
clear,
Part
(tomography):
transverse Part
2:
scan-
axial
Clinical
applica-
Brit. 7. Radiol., 1973, 46, 1023-1047. D. 0., and PRESSMAN, B. D. Computerized tomography of brain. Radiol. C/in. North Amertion.
2.
DAVIS,
ica, 1974, 3. HOUNSFIELD, axial
12,
297-313.
G.
scanning
N.
Computerized
transverse
(tomography):
tion of system.
Brit.
Part
7. Radiol.,
i.
1973,
Descrip46, 1016-
1022.
4.
NEW, DAVIS,
ized .
F. J., Scoi-r, W. R., SCHNUR, J. A., K. R., and ‘IAVERAS, J. M. Computeraxial tomography with EM! scanner.
P.
Radiology, 1974, 110, 109-123. Scorr, W. R., NEW, P. F. and
raphy
SCHNUR,
of
hemorrhage.
J.
A.
J.,
Computerized
intracerebral Radiology,
and 1974,
DAvIS, axial
K. tomog-
intraventricular ff2,
73-80.
R.,
